While there is no way to delete all of your Apple Messages conversations at once, there are a couple of work-arounds to try to save time and storage space. You can delete messages quickly using a hot key combination on your Mac and deleting your message cache, or by clearing out and deleting old messages from your iPhone or iPad.

Steps

Method1

Deleting on your iPhone or iPad

1

Tap the Settings icon. You can delete a lot of old messages at once by changing your Message History settings, then deleting your current conversations.

2

Tap Messages. You will have to scroll down on the menu screen to find it.

3

Tap Keep Messages. It's located under "Message History."

4

Tap 30 Days.

5

Tap Delete. Doing so will delete all messages and message attachments that are older than 30 days.

This may not delete all of your messages.

6

Tap the Messages icon from your home screen.

7

Tap Edit. It's located in the top left corner of the screen. Doing so will make round radio buttons appear next to each conversation.

8

Tap the radio button next to each conversation. Select all the conversations you wish to delete.

9

Tap Delete. Doing so will delete all the selected conversations at once.

Method2

Deleting on your Mac

1

Open the Messages app.

2

Click on the first chat thread. You will be deleting everything below the first chat thread you select.